Island



(No Model.)

G. W. STAFFORD. SHEDDING MECHANISM FOR LOOMS.

No. 415,686. Patented Nov. 19, 1889.

WITNESSES: I Q a N PETERS, Phulwlilhognrhor. Wallfingwn. 17.12v

UNITED STATES PATENT OFFICE.

GEORGE IV. STAFFORD, OF PROVIDENCE, RI'IODE ISLAND, ASSIGNOR TO THE GEO. STAFFORD MANUFACTURING COMPANY, OF SAME PLACE,

SHEDDINIG MECHANISM FOR LOOMS.

SPECIFICATION forming part of Letters Patent No. 415,686, dated November 19, 1889.

Application filed August 5, 1889. Serial No. 319,803. (No model.)

To a'ZZ whom it may concern:

Be it known that 1, GEORGE W. STAFFORD, of Providence, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Shedding Mechanism for Looms; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the ro'letters of reference marked thereon, which form a part of this specification.

. This invention refers to dobby mechanism for operating the heddle frames or harnesses of looms, and it is more particularly an improvement on the form of dobby shown in United States patent, of August 21, 1888, No. 388,318, though it is applicable to positivemotion (lobbies.

These improvements consist, mainly, in a modification of the pawl mechanism that operates the pattern-cylinder, and also of the plate-levers that are raised by the pins in the pattern-chain, whereby the pattern-chain for any particular pattern can be shortened; and

also in a modification of the mode of pivoting the jack-levers on the harness-levers to maintain the position of the lower latch-hooks when they are not in motion, and allow of a I relative increase of the mot-ion of the harness- 0 levers.

I11 the drawings, Figure 1 shows a .front elevation, partly in section, of the working parts of the dobby, the frame being left out. Fig. 2 is a top view of the ratchet-wheels on 5 the shaft of the pattern-cylinder and the pawls that move them. Fig. 3 shows a section of the pattern cylinder and chain with a pair of the plate-levers that are operated by them. Fig.4 is an end view of the parts shown in Fig. 3.

It will be seen by reference to Fig. 1 that the pattern mechanism has been changed from below the dobby-frame, its position in the patent before referred to, to a position on a level with the center pivots of the jack levers, and that two ratchet-wheels ll H, Fig. 2, are put on the shaft of the patterncylinder where one has heretofore been used, and two pawls K K are employed to 0p erate the ratchet-wheels. One of these pawls is pivoted to the rocker-lever 13 below its shaft T and the other pawl is pivoted to the rocker-lever above its shaft, by which it will readily be seen that one of the pawls moves the pattern-cylinder while the other pawl is going back from having moved it. The result of this is that there are two short motions given to the pattern-cylinder-one by the inward movement of the upper part of the rocker-lever B and the other by the inward motion of the lower part of that-lever.

These two short motions equal in extent the one long motion formerly given by one pawl pivoted on one end of the rocker-lever, and the advantage gained by using the two short motions is that whereas with one long motion it was necessary to indicate for two latch-hooks, an upper and a lower one, because both of them were likely to be required before another long motion of the pawl would be made with the two short motions it is only necessary to indicate for one latch-hook at each motion, thereby avoiding the trouble liable to be met with from indicating for a latch-hook before it was needed, as in case of a positivennotion dobby the hook indicated in advance would be free of its check-bar and be liable to be moved by the friction of the harnesses in motion and the causes before the lifter moved it.

The plate-levers are impairs, one of each pair to indicate for an upper latch-hook,which it raises by its inner end extended up for that purpose into contact with said upper latch hook, and the other for one of the lowerones, which it operates by means of a Wire connecting the lever with the hook, and one of each pair has the projection on its under side by which the pin in the pattern-chain raises it, placed just far enough in advance of the 0 like projection of the other one of the pair that as one row of pins raises one of a pair of levers the other one of the pair will be dropped bythe row of pins just passed. This is shown in Fig. 3,where the pin 0 on the bar 3 has just 5 raised the lever F and the lever F has just been dropped by the pin 0' in the same bar. In addition to the greater security of the hooks already mentioned, I am enabled to shorten the pattern-chain one-half in certain cases.

Owing to the limited space allowed for looms in mills, it is desirable to have all atbe shortened to bring the point where the power is exerted on the jack-lever nearer the point where it is pivoted to the harness-lever;

but in proportionas the jack-lever is shortened the rising movement of the lower end of the jack-lever,which occurs when the latch at the upper end thereof is engaged and moved outward by the upper lifter, increases. This upward movement of the jack-lever raises the pivot end of the lower latch, and turning said latch on the loop or bend of the wire, as on a fulcrum, tends to lower the hooked endthere' of into engagement with the lower lifter and thus occasion-outward movement of said latch and the lower end of the jack-lever with said lifter at a time when such movement may not be desired. To overcome this upward movement, I make a projection D on the jack-leve-r, which projection has an opening therein for the reception of the stud or pin 9 on the harness-lever, which constitutes the pivot of the jack-lever. This carries the center of motion of the jack-lever out of line with the end pivots of the latch-hooks, the effect of which is to produce a falling movement of thejack-lever while the upper end thereof swings outward, and to prevent any upward movement of the'end of the jack-lever that is in contact with its stop-bar.

Having thus described my improvements, what I claim as my invention, isl 1. In a shedding mechanism for looms, a series of plate-levers arranged in pairs, one of each pair having the projection by which it is raised by the pins in the pattern-chain placed in advance of the similar projection on the other lever of the same pair, combined with a pattern-chain cylinder provided with mechanism for moving it to indicate for the operation of the top and bottom hooks separately, substantially as and for the purpose specified.

2. In a shedding mechanism for looms, the combination of a pattern-cylinder provided with two ratchet-wheels, and two pawls to alternately move the pattern-cylinder by engagement with the said ratcl1et-wheels,witl1 a series of plate-levers arranged in pairs, one of each pair having the projection by which it is raised by the pins in the pattern-chain placed in advance of the similar projection on the other lover of the same pair, substantially as and fonthe purpose described;

The combination,with a harn ass-lever, of

a jack-leverpivoted-thereto andhaving latchhooks pivoted at the oppositeends of the same, the pivot by which the jack-lever is connected with the harness-lever being placed outside of the line passing through the pivots of the latch-hooks, as described.

GEO. V. STAFFORD.

\Yitncsses:

- CHARLES H. POLAND,

BENJ. ARNOLD. 

